Electronic and manual backup flow control systems

ABSTRACT

In various embodiments, an electronic flow selector of a fluid flow control system may be used to select a flow rate of a fluid. When the system is in an electronic mode, an encoder may electronically encode the fluid flow selection. A controller may receive the electronically encoded flow selection and transmit a corresponding control signal to an electronic valve to allow the fluid to flow at the selected flow rate. When the system is in a manual mode, backup manual flow selectors may be used to directly control the flow rate of a fluid. When the system is in a manual mode, the mechanical backup flow selectors may be in a deployed position. When the system is in an electronic mode, the mechanical backup flow selectors may be in a retracted position. Particular applications to gases and anesthesia delivery are disclosed herein.

TECHNICAL FIELD

This disclosure relates generally to controlling the flow of fluids viamanually adjustable controls. Particularly, this disclosure relates to amechanical backup flow control system for use with an electronic flowcontrol system.

SUMMARY

In various instances, the rates of flow of fresh gases, such as oxygen,nitrous oxide, and air, in modern anesthesia delivery systems may becontrolled by a practitioner either electronically or mechanically. Invarious embodiments, one or more flow selectors (e.g., rotatable knobs)may be configured to electronically select a flow rate of a gas when inan electronic mode. The anesthesia delivery system may also includemanual backup controls for controlling the flow rate of one or more ofthe gases when in an unpowered state. In one embodiment, three-wayselector valve and/or a combination of normally-open valves andnormally-closed valves may be used to selectively enable the flow of gasfrom either electronically controlled electronic proportional valves ormechanically operated needle valves.

For instance, when a fluid flow control system is in an electronic mode,a three-way selector valve, or other diversion valve system, may allowfluid from the electronically controlled electronic proportional valvesto be delivered to a patient. When the fluid flow control system is inan unpowered state or a manual override is selected, the three-wayselector valve may allow fluid from the mechanically controlled needlevalves to be delivered to a patient. Alternatively, a diversion valvesystem may include a combination of normally-open and normally-closedvalves instead of or in addition to a three-way selector valve, asdescribed herein. In some embodiments, the diversion valve system may belocated between a fluid supply and a fluid control valve. In otherembodiments, the diversion valve system may be located between a fluidcontrol valve and a fluid output.

An electronic flow control valve may be configured to selectivelyreceive a fluid from a fluid supply. An electronic flow selector mayallow a practitioner to select a flow rate of the first fluid via theelectronic flow control valve. For example, an encoder mayelectronically encode a selection made via the electronic flow selectorand transmit the encoded selection to an electronic controller. Theelectronic controller may transmit a control signal to the electronicflow control valve to control the flow rate of the fluid based on theselection made via the electronic flow selector. The electronic flowcontrol valve may include an electronic proportional valve and theelectronic flow selector may include a rotary knob configured to bemanually rotated by a practitioner. Alternatively, the electronic flowselector may include any of a wide variety of digital and/or analogselectors.

In some embodiments, a unique electronic flow control valve may be usedto control the flow rate of each available fluid. A unique electronicflow selector may be available to control the flow rate of each of theelectronic flow control valves. Alternatively, one or more of theelectronic flow selectors may be selectively assignable to control twoor more electronic flow control valves. For example, a system mayinclude three electronic flow control valves, one for oxygen, one forair, and one for nitrous oxide. The system may incorporate only twoelectronic flow selectors, one of which may be selectively used tocontrol either the flow rate of the air or the flow rate of the nitrousoxide. Any electronic flow selector may be permanently assigned orselectively assigned to control the flow rate of any one or more of theavailable fluids.

One or more mechanical flow control valves may be configured to controlthe flow rate of each of the available fluids. For example, a uniqueneedle valve may be used to mechanically control the flow rate of eachavailable fluid. A manual flow selector, such as a knob or slider, maybe actuated by a practitioner to mechanically adjust the flow ratethrough each of the needle valves. In some embodiments, the manual flowselectors may be disabled and/or retracted to prevent adjustments whenthe system is in an electronic mode.

Accordingly, in an electronic mode, one or more electronic flowselectors may be adjusted to control the flow rate of one or more fluidsthrough one or more electronic flow control valves. In the poweredstate, backup mechanical flow control valves may be disabled and/orotherwise prevented from supplying a fluid or combination of fluids.Moreover, in the powered state, manual flow selectors associated withthe backup mechanical flow control valves may be disabled and/orretracted to prevent adjustments.

In an unpowered state, or when a manual override selection is made, theelectronic flow control valves may be disabled and/or otherwiseprevented from supplying a fluid or combination of fluids. Manual flowselectors may be enabled and/or deployed to allow a practitioner tomanually control a flow rate of one or more fluids through the backupmechanical flow control valves.

In some embodiments, when the manual flow selectors are retracted, suchas upon power restoration or a reset of the system, the flow rate ofeach of the backup mechanical flow control valves may be reset to a homestate, in which a predetermined flow rate of a gas will automaticallyflow when the system enters an unpowered state.

In one embodiment, the electronic flow control valve may comprise anelectronically controlled stepper motor configured to adjust the flowrate of a fluid through a mechanical flow control valve, such as aneedle valve. In various examples provided herein, the fluid isdescribed as a gas, such as oxygen, nitrous oxide, and/or air. However,any of a wide variety of liquids and/or gases may be used in conjunctionwith various embodiments of the systems and methods described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagram of an anesthesia delivery system configuredwith electronic and backup manual controls for controlling the flow ofoxygen, nitrous oxide, and air.

FIG. 2A illustrates an anesthesia delivery machine configured with threemanual flow selectors, one each for controlling the flow of oxygen,nitrous oxide, and air.

FIG. 2B illustrates an anesthesia delivery machine configured with twoelectronic flow control selectors, configurable to selectively controleach of the three gases, and three backup manual flow selectors, forcontrolling each of the three gases.

FIG. 3 illustrates a close-up view of a control panel of an anesthesiadelivery machine, including two electronic flow control selectorsselectively configurable to control either oxygen and nitrous oxide, oroxygen and air.

FIG. 4 illustrates a wider view of a control panel of an anesthesiadelivery machine, including backup manual flow controls for controllingthe flow of three gases independently.

FIG. 5 illustrates an exemplary embodiment of backup manual flowselectors in a retracted state and the backup manual flow selectors in adeployed state.

FIG. 6 illustrates another view of a control panel of an anesthesiadelivery machine, including both electronic flow control selectors andbackup manual flow selectors.

FIG. 7 illustrates a mechanical apparatus configured to selectivelydeploy and retract three manual flow selectors.

FIG. 8 illustrates a deployment assembly configured to selectivelydeploy the manual flow selectors.

FIG. 9 illustrates a top view of three manual flow selectors andassociated needle valve assemblies for controlling the flow rate ofthree gases.

FIG. 10 illustrates a bottom view of three manual flow selectors andassociated needle valve assemblies for controlling the flow rate ofthree gases.

FIG. 11 illustrates carriage and rail assembly configured to slidablyconnect the flow selector assembly to a deployment assembly.

FIG. 12 illustrates a cut-away view of various components within adeployment assembly configured to selectively deploy manual flowselectors within a flow selector assembly.

FIG. 13 illustrates a cut-away view of a deployment assembly with a flowselector assembly in a deployed state.

FIG. 14 illustrates a cut-away view of a portion of the deploymentassembly.

FIG. 15 illustrates a cut away view of a flow selector assembly in whichdetect switches confirm that the mechanical needle valves are in a homestate.

FIG. 16 illustrates a view of a flow selector assembly with positiondetectors configured to selectively detect the relative location ofvalve shafts and associated flow rates.

FIG. 17 illustrates an embodiment of a flow selector assembly configuredwith a home state assembly configured to return the needle valves to ahome state when the deployment assembly retracts the flow selectorassembly.

DETAILED DESCRIPTION

While electronic flow control of gases may be useful during anesthesiadelivery, it may be desirable to provide manual backup controls as well.For example, in the event of power loss, it may be desirable to continuesupplying gases during anesthesia delivery. In some embodiments,electronic controls, such as trim knobs, used in conjunction withencoders, may facilitate the electronic adjustment of the flow rate ofone or more gases during anesthesia delivery. Separate backup knobs maybe available for use in the event of power failure or powerunavailability. In such embodiments, the practitioner may need to engagethe backup knobs, switch the machine from an electronic mode to a manualmode, and/or ensure that the manual knobs are set to a desirable stateprior to switching to a manual mode.

Power loss during anesthesia delivery may be confusing and/or disruptiveduring a critical medical procedure. It may be an inconvenience and/orconfusing for a practitioner to see two sets of knobs for controllingthe same set of gases. In various embodiments of the present disclosure,flow selectors, such as rotary knobs, may be electronically operablewhen a fluid flow control system is in an electronic mode and backupflow selectors may be retracted or otherwise disabled when a fluid flowcontrol system is in an electronic mode. In an unpowered state, or whena practitioner engages the backup system, the backup flow selectors maybe deployed or otherwise enabled.

The number of diversion valve systems, mechanically operated valves,electronically operated valves, controllers, encoders, flow selectors,and/or other components described herein may correspond to the number ofgases (or liquids) available. In various anesthesia delivery systems,oxygen, nitrous oxide, and/or air may each be independently controllableand/or proportionally controllable. A mixture of one or more gases maybe used in conjunction with a vaporizer to deliver anesthesia.

In one embodiment, a diversion valve system may direct the flow of a gas(or liquid) from a gas supply to either a mechanical flow control valve,such as a mechanically operated needle valve, or an electronic flowcontrol valve, such as an electronic proportion valve, depending onwhether or not the system has power or if a backup system has beenengaged.

If the system is in an electronic mode, the selected flow rate may beencoded and transmitted to a controller. The controller may then send acontrol signal to the electronic proportion valve in order to achievethe selected flow rate. A deployment assembly may maintain the backupflow control valves in a retracted state. Alternatively, a deploymentassembly may maintain the backup flow control valves in a disabled ornon-functioning state.

If the system is in an unpowered state or a backup system is engaged bya practitioner, the backup flow selectors may be deployed, enabled,and/or otherwise caused to function. A selected flow rate may then bemechanically translated from a manual flow selector to a mechanicallyoperated flow control valve, such as a needle valve, to achieve theselected flow rate.

According to various embodiments, the diversion valve system may includenormally-open and normally-closed valves in order to selectively preventthe gas from flowing from (or to) both the mechanically operated needlevalve and the electronic proportion valve. The diversion valve systemmay be implemented using any of a wide variety of valves and/or controlsystems, such as a three-way selector valve.

In some embodiments, the needle valve may be used as the mechanical flowcontrol valve and the same needle valve in combination with theelectronic stepper motor may be considered the electronic flow controlvalve. In various embodiments, the flow selector may comprise any of awide variety of knobs, buttons, rotatable actuators, slides, and/orother analog and/or digital selection devices. In various embodiments, acontroller or control system may be implemented as any combination ofhardware, firmware, and/or software. For example, a controller may beimplemented as a field-programmable gate array (FPGA). In someembodiments, an electronic controller for transmitting a control signalto an electronic flow control valve may be distinct from otherelectronic components in a gas flow control system, such asmicroprocessors and other electronic components associated withdisplays, touch screens, data storage, data connectivity, etc. Thereliability of the electronic flow controls may be improved byseparating the electronic flow controls from other electronic featuresof an anesthesia delivery device and/or by implementing it in hardwarerather than software.

While the various examples and embodiments disclosed herein aredescribed in conjunction with a gas flow control system, many of theembodiments could be used or modified for use with any type of fluid,including various gases and liquids. Gases used for anesthesia delivery,such as oxygen, nitrous oxide, and air, are used herein as examples ofgases that can be controlled via the presently described fluid flowcontrol systems and are referred to as gas flow control systems.

Some of the infrastructure that can be used with embodiments disclosedherein is already available, such as general-purpose computers, computerprogramming tools and techniques, digital storage media, andcommunication networks. A computing device or other electroniccontroller may include a processor, such as a microprocessor, amicrocontroller, logic circuitry, and/or the like. The processor mayinclude a special purpose processing device such as application-specificintegrated circuits (ASIC), programmable array logic (PAL), programmablelogic array (PLA), a programmable logic device (PLD), FPGA, or anothercustomizable and/or programmable device. The computing device may alsoinclude a machine-readable storage device, such as non-volatile memory,static RAM, dynamic RAM, ROM, CD-ROM, disk, tape, magnetic, optical,flash memory, or other machine-readable storage medium. Various aspectsof certain embodiments may be implemented using hardware, software,firmware, or a combination thereof.

The embodiments of the disclosure will be best understood by referenceto the drawings, wherein like parts are designated by like numeralsthroughout. The components of the disclosed embodiments, as generallydescribed and illustrated in the figures herein, could be arranged anddesigned in a wide variety of different configurations. Furthermore, thefeatures, structures, and operations associated with one embodiment maybe applicable to or combined with the features, structures, oroperations described in conjunction with another embodiment. In otherinstances, well-known structures, materials, or operations are not shownor described in detail to avoid obscuring aspects of this disclosure.

Thus, the following detailed description of the embodiments of thesystems and methods of the disclosure is not intended to limit the scopeof the disclosure, as claimed, but is merely representative of possibleembodiments. In addition, the steps of a method do not necessarily needto be executed in any specific order, or even sequentially, nor do thesteps need to be executed only once.

FIG. 1 illustrates a diagram 100 of an anesthesia delivery systemconfigured with electronic flow control valves 111, 112, and 113 andbackup mechanical flow control valves 101, 102, and 103 for controllingthe flow of oxygen 121, nitrous oxide 122, and air 123. When power isavailable via AC supply 160 and/or batteries 161, the anesthesiadelivery system may utilize electronic flow control valves 101, 102, and103 controlled by one or more electronic flow selectors. The power inputmay be converted and/or inverted as necessary by a power board 179and/or motherboard 175. A gas flow board 150 may include variousmonitoring and/or control components for electronically monitoring,regulating, and/or controlling the flow of gases within the anesthesiadelivery system.

In various embodiments, the anesthesia delivery system may includevarious components and/or interface with various components via the gasflow board 150. For example, the gas flow board 150 may include and/orcommunicate with various FPGA's, CPUs, microprocessors, logic circuits,drive circuits, digital to analog converters, analog to digitalconverters, drive circuits, motor drivers, power switches, inputdevices, optical sensors, visual indicators, displays, solenoids,stepper motors, touch panels, and/or peripheral devices. Additionally,the gas flow board 150 may include and/or communicate with positionswitches, LED, needle valve switches, gas source, and/or other selectioninputs. A practitioner may interact with the anesthesia delivery machineby providing inputs with regards to a flow of one or more gases. Forinstance, a practitioner may provide an input via an electronic flowselector. The electronic flow selector may comprise a mechanicallyrotatable knob and a rotary encoder.

When the anesthesia delivery system is in an electronic mode, the usermay utilize an electronic mode or select a manual mode. When theanesthesia delivery system is in an unpowered state, the anesthesiadelivery system may be used in a manual mode. In the electronic mode,the three source gases, oxygen 121, nitrous oxide, 122, and air 123, mayflow through the electronic flow control valves 111, 112, and 113, anoxygen ratio controller 125, and/or check valves 130 and flow sensors.In a manual mode, the three source gases 121, 122, and 123 may flowthrough backup mechanical flow control valves 101, 102, and 103, oxygenratio controller 125, and/or backpressure valve 127.

In various embodiments, a user may achieve a desired ratio of gases 121,122, and 123 by starting with zero flow and sequentially adding sourcegases to the total flow, noting the effect of each on total flow rate.In an alternative embodiment, the user may achieve a desired ratio ofgases 121, 122, and 123 by starting at a “home state” flow of oxygen 121and then adjust each of the gases 121, 122, and 123 to achieve thedesired flow rate. The oxygen ratio controller 125 may ensure aclinically safe ratio of oxygen to nitrous oxide and/or oxygen to air.The check valves 130 may prevent back flow of gases 121, 122, and 123due to potential higher downstream pressures.

According to various embodiments, a user may select a flow rate of acombination of oxygen and air to be supplied to a patient. A user mayalso select a flow rate of nitrous oxide to be provided to a patientinstead of air. In some embodiments, the nitrous oxide may be suppliedin addition to air. Regardless of the selections made by a user, a safeamount of oxygen may be automatically supplied to the patient, asensured by the oxygen ratio controller (ORC) 125.

In either flow control mode, after passing through the check valves 130,the flows of the three gases 121, 122, and 123 may be combined into asingle flow, which may be measured by a total flow meter, and passthrough a total flow meter 137. An anesthetic gas vaporizer 140 mayvaporize an anesthetic into the gases. A three-way selector valve 135may be used to direct a flow of gases from only one of the backupmechanical flow control valves 101, 102, and 103 and the electronic flowcontrol valves 111, 112, and 113. Alternatively, the three-way selectorvalve may comprise a one or more normally-open and/or normally-closedvalves. Alternative diversion valve systems may be employed in place ofa three-way selector valve 135 and/or normally-open and/ornormally-closed valves.

In an electronic mode, flow control selectors associated with the backupmechanical flow control valves 101, 102, and 103 may be disabled,retracted, locked, and/or otherwise disengaged. In a manual mode(whether entered due to power loss or user selection), flow controlselectors associated with the needle valves 101, 102, and 103 may beenabled, deployed, unlocked, and/or otherwise engaged. Various elementsof the diagram 100 are illustrated in the key 190 and are not describedin detail herein. Additionally, any of a wide variety of components,measurement devices, monitoring devices, and/or control devicesconfigured for use in anesthesia delivery systems, gas delivery systems,liquid delivery systems, and/or other related systems may be added to,supplemented within, and/or replace components within the illustratedsystem.

FIG. 2A illustrates an anesthesia delivery machine 200 configured withthree manual flow selectors 250, one each for controlling the flow ofoxygen, nitrous oxide, and air. The illustrated anesthesia deliverymachine 200 may include a breathing system 210, anesthetic gasvaporizers 230, and/or other components of an anesthetic deliverysystem. The anesthesia delivery machine 200 may include a cart 240and/or wheels 245 for portability. An electronic display 220 may provideinformation regarding the flow rate and/or anesthetic delivery processto a practitioner. Additionally, the electronic display 220 may beconfigured as a touch sensitive display to allow a practitioner toprovide a selection of a flow rate.

FIG. 2B illustrates an anesthesia delivery machine 299 configured withtwo electronic flow control selectors 251, configurable to select a flowrate for each of the three gases, and three backup manual flow selectors260, for controlling each of the three gases. Similar to the embodimentillustrated in FIG. 2A, the anesthesia delivery machine 299 may includea breathing system 210, anesthetic gas vaporizers 230, and/or othercomponents of an anesthetic delivery system. The anesthesia deliverymachine 299 may include a cart 240 and/or wheels 245 for portability. Anelectronic display 220 may provide information regarding the flow rateand/or anesthetic delivery process to a practitioner. Additionally, theelectronic display 220 may be configured as a touch sensitive display toallow a practitioner to provide a selection of a flow rate.

The three backup manual flow selectors 260 may remain retracted and/ordisabled when the anesthesia delivery machine 299 is in an electronicmode. When the anesthesia delivery machine 299 enters a manual mode(e.g., due to power loss or a user selection), the three backup manualflow selectors 260 may be deployed, unlocked, and/or otherwise function.As previously described, various internals, switches, normally-openvalves, normally-closed valves, three-way valves, and/or othercomponents may regulate the flow of gases within the anesthesia deliverymachine 299 based on whether it is in a manual mode or an electronicmode.

FIG. 3 illustrates a close-up view of a control panel 300 of ananesthesia delivery machine, including two electronic flow controlselectors 315 and 317 selectively configurable to control either oxygenand nitrous oxide, or oxygen and air. As illustrated, the anesthesiadelivery machine may include a panel 330 to display various telemetrydata associated with a patient, information associated with the flowrate of gases, and/or information associated with the delivery of one ormore anesthetics. Various inputs 340 may be available to change thedisplay of panel 330 and/or to control the anesthesia delivery machine.

In a first position, a selection toggle 310 may allow a practitioner tocontrol the flow rate of oxygen and nitrous oxide via the respectiveelectronic flow control selectors 315 and 317. In a second position, theselection toggle 310 may allow a practitioner to control the flow rateof oxygen and air via the respective flow control selectors 315 and 317.Depending on the position of the selection toggle 310, various flow ratemonitoring devices and ratio measuring devices 320, 325 and 327 mayindicate the flow rate of one or more gases and/or combination of gases.In various embodiments, auxiliary inputs and outputs 350 for oxygenand/or another gas may be available.

While the illustrated embodiment shows two electronic flow controlselectors 315 and 317, any number of flow selectors and associated gasesmay be utilized. For example, a flow control system may be configured toallow for the electronic and backup manual control of one, two, three,four . . . or N number of gases or liquids. In some embodiments, morethan one flow control selector (e.g., knob, toggle, dial, slider,switch) may be configured to control the flow rate of the same gas.Additional selection toggles 310 and/or a multi-position selectiontoggle, may be used to control the number of gases controlled by anynumber of corresponding flow control selection knobs. The flow controlselectors may include and/or utilize any analog or digital selectionmechanism for selecting a flow rate, including knobs as illustrated inthe figures.

FIG. 4 illustrates a wider view of a control panel 400 of an anesthesiadelivery machine, including backup manual flow controls 481, 482, and483 for controlling the flow of three gases independently. When theanesthesia delivery system is in an electronic mode and the user has notselected a manual mode, the anesthesia delivery system may be in anelectronic mode. In an electronic mode, two electronic flow controlselectors 415 and 417 may be used to control either oxygen and nitrousoxide or oxygen and air, depending on the selection made via a selectiontoggle. An electronic display 430 may display information associatedwith the flow rate of one or more gases, an anesthetic, and/or patienttelemetry data. Various touch inputs 440 may be available. An auxiliarycontrol panel 450 may allow for one or more gases to be supplied to anauxiliary device.

When the anesthesia delivery system is in an unpowered state and/or theuser has selected a manual mode, the anesthesia delivery system may bein a manual mode. In a manual mode, the flow rate of one or more gasesand/or the amount of anesthetic delivery may be controlled via a manualpanel 455. The electronic display 430, the touch inputs 440, theelectronic flow control selectors 415 and 417, and other electroniccomponents may be unavailable in an unpowered state and one or more ofthem may be unavailable and/or otherwise disabled in a manual modeselected when in a powered state.

The manual panel 455 may include a total flow rate indicator 490, amanual mode selector 485 (e.g., a spring-loaded plunger), and one ormore manually operated flow control selectors 481, 482, and 483.According to various embodiments, a manually operated flow controlselector may be available for each available gas or for each availablecritical gas. In various embodiments, manually operated flow controlselectors 481, 482, and 483 may be disabled, retracted, locked, and/orotherwise not operational when the anesthesia delivery system is in anelectronic mode. In a manual mode, the manually operated flow controlselectors 481, 482, and 483 may be enabled, deployed, unlocked, and/orotherwise become operational.

FIG. 5 illustrates an exemplary embodiment 500 of backup manual flowselectors 510, 520, and 530 in a retracted state 501 and the backupmanual flow selectors 510, 520, and 530 in a deployed state 502. Theillustrated embodiment includes a perspective view (top of 501 and 502)and a front view (bottom of 501 and 502). As illustrated, a total flowindicator 550 may be available to indicate the flow rate of one or moregases. A manual mode selector 540 may allow a user to cause ananesthesia delivery system to enter a manual mode even when the systemis in a powered state. The system may automatically enter a manual modewhen the system transitions from a powered state to an unpowered state.In an electronic mode, the flow control selectors 510, 520, and 530 mayremain in a retracted state (501), so as to be unobtrusive, disabled,and/or otherwise not inconvenience or confuse a user. In a manual mode,the flow control selectors 510, 520, and 530 may be deployed (502), soas to be more obtrusive, enabled, and/or otherwise alert a user thatthey may be used to control the flow rate of one or more gases.

In some embodiments, the default position of a manual flow controlselector may be above 0 liters per minute. For example, a defaultposition for a manual flow control selector associated with the flowrate of oxygen may have a home state of 2 liters per minute, so as tocontinue providing a critical gas to a patient even in the event theanesthesia delivery system loses power during use.

FIG. 6 illustrates another view of a control panel of an anesthesiadelivery machine that includes both electronic flow control selectors615 and 617 and backup manual flow selectors 610, 620, and 630. In anelectronic mode, backup manual flow selectors 610, 620, and 630 may beretracted, locked, disengaged, and/or otherwise non-operational. Theflow rate of two or more gases may be controlled by the electronic flowcontrol selectors 615 and 617. An optimizer indicator 612 may indicate atotal flow rate of gases selected by the electronic flow controlselectors 615 and 617.

The anesthesia delivery system may enter a manual mode due to the lossof power and/or in response to a user selecting a manual mode selector640. In one embodiment, the manual mode selector 640 may include aplunger configured to actuate a solenoid or motor to deploy the manualflow selectors 610, 620, and 630. In a manual mode, a flow rateindicator 650 may indicate the total flow rate of gases as selected bythe backup manual flow selectors 610, 620, and 630.

FIG. 7 illustrates a mechanical apparatus 700 configured to selectivelydeploy and retract three manual flow selectors 710, 720, and 730.According to various embodiments, the mechanical apparatus 700 may bemounted within a housing of an anesthesia delivery system and/or otherfluid flow control system. The embodiments of the mechanical apparatus700 and related embodiments are described herein in conjunction with ananesthesia delivery system and/or other fluid flow control system.However, the mechanical apparatus 700 could be utilized in conjunctionwith any system or apparatus in which it may be useful to have buttons,knobs, or other selectors selectively deployed and retracted in responseto user selection and/or power availability.

As illustrated, a deployment assembly 760 may be mated with a flowselector assembly 770. The flow selector assembly may include one ormore (illustrated as three) manual flow selectors 710, 720, and 730. Aknob guard 740 may prevent the manual flow selectors 710, 720, and 730from being actuated when in a retracted state. The deployment assembly760 may be configured to selectively deploy the flow selector assembly770 by translating the flow selector assembly 770 from a retractedposition to a deployed position. A manual mode selector 750 may be usedto manually select a deployed position. Additionally, the deploymentassembly 760 may be configured to deploy the flow selector assembly 770in response to a power disruption.

FIG. 8 illustrates a deployment assembly 800 configured to selectivelydeploy a flow selector assembly (not shown). The deployment assembly 800may include a front support plate 823 configured to fasten themechanical apparatus to an anesthesia machine (or other device). A latchsupport block 815 and a solenoid 819 may be mounted to a bottom supportplate 817. A motor 810 may be mounted to the bottom support plate 817via a motor mount 812. A button plunger (a manual mode selector) 850 maybe mounted to the front support plate 823 and operable to engagecomponents within the latch support block to disengage a latch connectedto the solenoid, as described in detail below.

FIG. 9 illustrates a top view 900 of three manual flow selectors 910,920, and 930 and associated needle valve assemblies 950, 951, and 952for controlling the flow rate of three gases. In the illustratedembodiments, the manual flow selectors 910, 920, and 930 are illustratedas rotatable knobs. In alternative embodiments, the manual flowselectors may be configured as any of a wide variety of mechanicalcontrol selectors configured to directly adjust the flow rate of amechanically controlled flow control valve. For example, the manual flowselectors 910, 920, and 930 may be configured as rotatable knobs,ratcheting knobs, dials, sliders, rotary switches, and the like.

A knob guard 940 may prevent each of the manual flow selectors 910, 920,and 930 from being actuated when in a retracted state, restrain axialmotion relative to the front panel, and protect the manual flowselectors 910, 920, and 930.

FIG. 10 illustrates a bottom view 1000 of three manual flow selectors1010, 1020, and 1030 and associated needle valve assemblies 1051, 1052,and 1053 for controlling the flow rate of three gases. Again, a knobguard 1040 may prevent each of the manual flow selectors 1010, 1020, and1030 from being actuated when in a retracted state, prevent axial motionof the manual flow selectors 1010, 1020, and 1030 relative to the frontpanel, and protect the manual flow selectors 1010, 1020, and 1030. Theknob guard 1040 may be configured to eliminate or reduce potential pinchpoints during the retraction and/or deployment of the manual flowselectors 1010, 1020, and 1030.

According to various embodiments, each manual flow selector 1010, 1020,and 1030 may have a non-circular recess that engages a correspondingnon-circular tip of each respective needle valve 1051, 1052, and 1053shaft configured to allow the needle valves 1051, 1052, and 1053 to moveaxially, independent of the manual flow selectors 1010, 1020, and 1030.Accordingly, the flow rate may be adjusted through axial displacement ofeach needle valve, yet remain rotationally connected to the knob inorder to transmit the manual application of torque from a user.

As illustrated, each needle valve 1051, 1052, and 1053 may include arespective valve stop plunger 1061, 1062, and 1063 and position switch1071, 1072, and 1073, which may function to detect when each respectiveneedle valve 1051, 1052, and 1053 is fully closed or in a home state, asdescribed herein.

FIG. 11 illustrates an assembly 1100 including a carriage 1155 and rail1165 configured to slidably connect the flow selector assembly 1170 to adeployment assembly (not shown). As illustrated, the flow selectorassembly 1170 may include one or more (shown as three) manual flowselectors 1110, 1120, and 1130. A knob guard 1140 may prevent the manualflow selectors 1110, 1120, and 1130 from being actuated when in aretracted state, restrain axial motion relative to the front panel, andprotect the manual flow selectors 1110, 1120, and 1130.

The carriage 1155 and rail 1165 assembly may be configured to slidablyconnect the flow selector assembly 1170 to a deployment assembly, suchthat the deployment assembly may slidably deploy the flow selectorassembly by translating the carriage 1155 along the rail 1165. Inalternative embodiments, the carriage 1155 and rail 1165 assembly may bereplaced using another mechanism adapted for translating one apparatusrelative to another apparatus.

FIG. 12 illustrates a mechanical apparatus 1200 cut-away view of variouscomponents within a deployment assembly 1270 configured to selectivelydeploy manual flow selectors 1210, 1220, and 1230 of a flow selectorassembly 1260. As illustrated, the flow selector assembly 1260 may belatched in a retracted state by a solenoid latch pin 1276 secured withina first recess 1274 of a junction block 1272. Position switch(es) 1280may detect the location of junction block 1272 in order toelectronically or mechanically confirm the retracted state of the flowselector assembly 1260.

As illustrated, the flow selector assembly 1260 may be released anddeployed by either an actuation of a manual override selector 1250 or bythe actuation of solenoid 1277. If the manual override selector 1250 isactuated, an angled surface of a plunger 1278 may interact with thelatch pin 1276, causing it to slide out of the first recess 1274 of thejunction block 1272. If the manual override selector 1250 is pushed insufficiently far and with sufficient force, the latch pin 1276 maydisengage from the first recess 1274.

Alternatively, in response to a power failure, electronic failure,mechanical failure, software error, an electronic override selection,and/or other disruptive event, the solenoid 1277 and the latch pin 1276may be pulled out of the first recess 1274, causing the system to entera manual mode. In such situations, the junction block 1272 may bereleased from the locking effects of the latch pin 1276 and translateforward due to the force exerted by a deployment spring 1284. That is,the deployment spring 1284 may cause the junction block to translateforward. The flow selector assembly 1260, secured to the junction block1272 on the rail and carriage assembly (see FIG. 11), may transitionfrom the retracted state to a deployed state in which the flow controlselectors 1210, 1220, and 1230 extend outward. The latch pin 1276 mayengage the second recess 1275 and thereby lock the junction block in thedeployed state.

According to the illustrated embodiment, in order to return to theretracted state, the solenoid 1277 may pull the latch pin 1276 from thesecond recess 1275 and the motor 1271 may pull the junction block backto a retracted state with the deployment spring 1284 in a compressedposition. The latch pin 1276 may then lock the junction block in theretracted state by engaging the first recess 1274.

FIG. 13 illustrates the mechanical apparatus 1300, including a cut-awayview of a deployment assembly 1370 with a flow selector assembly 1360 ina deployed state. As illustrated, the latch pin 1376 may engage thesecond recess 1374 to maintain the flow selector assembly in a deployedstate until the solenoid 1377 is actuated. A spring loaded 1390 crosspin 1388 may engage a collar 1386 to prevent the plunger 1378 from beingactuated via the plunger interface 1350.

Again, the position switch(es) 1380 may electronically and/ormechanically confirm that the junction block 1372 (and accordingly theflow selector assembly) is in a forward and deployed state. Flow controlselectors 1310, 1320, and 1330 may then be used to manually adjust theflow rate of one or more gases by actuating and adjusting mechanicallyoperated flow control valves, such as needle valves.

FIG. 14 illustrates a cut-away view 1400 of a portion of the deploymentassembly 1470 and the flow control assembly 1460. As illustrated, amotor 1471 may apply a torque to a threaded shaft 1485 to apply atranslating force, via a threaded bushing 1487, to the junction block1472. The force may be sufficient to overcome the deploying force of thedeployment spring 1484. The button 1450 and associated plunger may beeffectively reset for subsequent actuation. Manual flow controlselectors 1410 and 1420 may be retracted in conjunction with theretraction of the junction block 1472.

FIG. 15 illustrates a cut away view of a flow selector assembly 1500 inwhich a detect switch 1550 confirms that a mechanical needle valve 1551is in a home state by detecting a location with an axially-floatingbushing 1555. According to various embodiments, the mechanical needlevalve 1551 may be adjustable between a fully closed state, in which nogas flows, a fully open state, in which a maximum amount of gas flows,and any flow rate therebetween. In some embodiments, a needle valve maybe configured to enter a home state when the flow control selector 1520is retracted. The home state may correspond to a predetermined defaultflow rate.

A three-way selector valve (or other diversion valve system) may preventany actual gas from flowing when the flow control selector 1520 isretracted. Accordingly, when the flow control selector 1520 is deployed,it may automatically allow an amount of gas corresponding to the homestate of the mechanical needle valve 1551 to flow. For example, the homestate may correspond to a flow rate of oxygen of 2 liters per minute anda flow rate of nitrous oxide and/or air of 0 liters per minute. Variouspossible home state flow rates are possible for each available gas.

FIG. 16 illustrates another view of a flow selector assembly 1600 withposition detectors (detect switches 1671, 1672, and 1673) configured toselectively detect the relative location of valve shafts 1691, 1692, and1693. The position detectors 1671, 1672, and 1673 may be configured todetect whether or not they are engaged with protrusions (such asprotrusion 1663) on a groove 1661, 1662, and 1663 on a bushing 1665,1666, and 1667.

In the illustrated embodiment, needle valves 1651 and 1652 may be fullyclosed with the valve shafts 1691 and 1692 fully translated toward theneedle valves 1651 and 1652. Accordingly, position detectors 1671 and1672 may engage a protrusion (not illustrated) and detect that theneedle valves 1651 and 1652 are fully closed. Valve shaft 1693 may befully translated toward the flow selector 1630, causing needle valve1653 to be fully opened. Position detector 1673 may not be engaged withprotrusion 1663, and therefore detect that the needle valve 1653 is notfully closed.

FIG. 16 also shows three possible embodiments of valve shaft shapes. Afirst valve shaft 1693 may be hexagonal in shape and configured toengage a hexagonal cavity 1683 of a flow selector 1630. A second valveshaft 1692 may be rectangular in shape and configured to engage arectangular cavity 1682 of a flow selector 1620. A third valve shaft1691 may be circular in shape and include two protrusions configured toengage corresponding inclusions in a round cavity of a flow selector1610. According to various embodiments, the cavities 1681, 1682, and1683 may rotationally engage the valve shafts 1691, 1692, and 1693, butleave the valve shafts 1691, 1692, and 1693 free to axially translaterelative to the flow selectors 1610, 1620, and 1630. In variousembodiments, a knob guard 1640 may prevent axial translation of the flowselectors 1610, 1620, and 1630.

In some embodiments, locking mechanisms (not shown) may be utilized toselectively prevent the needle valves 1651, 1652, and 1653 from beingactuated. The locking mechanisms may be automatically disengaged whenthe flow selectors 1610, 1620, and 1630 are deployed. Alternatively, thelocking mechanisms may be independently engaged and disengaged by auser.

FIG. 17 illustrates an embodiment of a flow selector assembly 1700configured with a home state assembly 1771 configured to return theneedle valves to a home state when the deployment assembly retracts theflow selector assembly. According to various embodiments, the needlevalves may be adjustable between a fully closed state, in which no gasflows, a fully open state, in which a maximum amount of gas flows, andany flow rate therebetween. In some embodiments, one or more of theneedle valves may be configured to enter a home state when the flowcontrol selectors 1710, 1720, and 1730 are retracted. The home state maycorrespond to a predetermined default flow rate of one or more gases. Asillustrated, upon retraction of the flow control assembly 1700, a homestate assembly 1771 may slidably engage gears 1751, to cause the needlevalves to return to a default flow rate.

As previously described, a three-way selector valve (or other diversionvalve system) may prevent any actual gas from flowing when a flowcontrol selector is retracted. In such an embodiment, when the flowcontrol selector assembly is deployed, it will automatically allow anamount of gas corresponding to the home state of the needle valve toflow. For example, the home state may correspond to a flow rate ofoxygen of 2 liters per minute and a flow rate of nitrous oxide and/orair of 0 liters per minute. Various possible home state flow rates arepossible for each available gas.

A gas flow control system, according to any of the various embodimentsdescribed herein, may be used in conjunction with any of a wide varietyof applications. In the illustrated embodiments, the gas flow controlsystems are shown as parts of anesthesia delivery systems. In suchembodiments, the combined flow of one or more gases may be injected orotherwise infused with anesthesia, such as via a vaporizer, for acontrolled delivery of the anesthesia and/or the one or more gases to apatient.

This disclosure has been made with reference to various exemplaryembodiments, including the best mode. However, those skilled in the artwill recognize that changes and modifications may be made to theexemplary embodiments without departing from the scope of the presentdisclosure. While the principles of this disclosure have been shown invarious embodiments, many modifications of structure, arrangements,proportions, elements, materials, and components may be adapted for aspecific environment and/or operating requirements without departingfrom the principles and scope of this disclosure. These and otherchanges or modifications are intended to be included within the scope ofthe present disclosure.

The foregoing specification has been described with reference to variousembodiments. However, one of ordinary skill in the art will appreciatethat various modifications and changes can be made without departingfrom the scope of the present disclosure. Accordingly, this disclosureis to be regarded in an illustrative rather than a restrictive sense,and all such modifications are intended to be included within the scopethereof. Likewise, benefits, other advantages, and solutions to problemshave been described above with regard to various embodiments. However,benefits, advantages, solutions to problems, and any element(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, a required, or anessential feature or element. The scope of the present invention should,therefore, be determined by the following claims.

What is claimed is:
 1. A fluid flow control system, comprising: anelectronic flow control valve configured to selectively receive a firstfluid from a first fluid supply; an electronic flow selector configuredto allow for a selection of a flow rate of the first fluid from thefirst fluid supply via the electronic flow control valve; a controllerconfigured to transmit a control signal to the electronic flow controlvalve to cause the electronic flow control valve to allow the firstfluid to flow at the flow rate selected via the electronic flowselector; a mechanical flow control valve configured to selectivelyreceive the first fluid from the first fluid supply; a manual flowselector configured to control a flow rate of the first fluid from thefirst fluid supply via the mechanical flow control valve; and anactivation mechanism configured to: inhibit the operation of the manualflow selector when the fluid flow control system is in an electronicmode; and enable the operation of the manual flow selector when thefluid flow control system is in a manual mode.
 2. The fluid flow controlsystem of claim 1, wherein the activation mechanism comprises adeployment mechanism configured to: deploy the manual flow selector whenthe fluid flow control system is in the manual mode; and retract themanual flow selector when the fluid flow control system is in theelectronic mode.
 3. The fluid flow control system of claim 1, whereinthe activation mechanism comprises a locking mechanism configured to:lock the manual flow selector to prevent adjustments when the fluid flowcontrol system is in the electronic mode; and unlock the manual flowselector to allow adjustments when the fluid flow control system is inthe manual mode.
 4. The fluid flow control system of claim 1, furthercomprising a diversion valve system configured to: prevent the flow ofthe first fluid through the mechanical flow control valve and allow theflow of the first fluid through the electronic flow control valve whenthe fluid flow control system is in the electronic mode; and allow theflow of the first fluid through the mechanical flow control valve andprevent the flow of the first fluid through the electronic flow controlvalve when the fluid flow control system is in the manual mode.
 5. Thefluid flow control system of claim 4, wherein the diversion valve systemcomprises a three-way selector valve.
 6. The fluid flow control systemof claim 4, wherein the diversion valve system comprises: anormally-open valve configured to allow the flow of the first fluidthrough the mechanical flow control valve when the fluid flow controlsystem is in the manual mode; and a normally-closed valve configured toprevent the flow of the first fluid through the electronic flow controlvalve when the fluid flow control system is in the manual mode.
 7. Thefluid flow control system of claim 1, further comprising a vaporizerconfigured to inject an anesthetic into the first fluid, and wherein thefirst fluid comprises a gas.
 8. The fluid flow control system of claim1, wherein the electronic flow control valve comprises an electronicproportional valve.
 9. The fluid flow control system of claim 1, whereinthe mechanical flow control valve comprises a needle valve.
 10. Thefluid flow control system of claim 1, wherein the mechanical flowcontrol valve comprises a needle valve and the electronic flow controlvalve comprises a stepper motor configured to electronically control theneedle valve.
 11. The fluid flow control system of claim 1, wherein themanual flow selector comprises a rotatable knob.
 12. The fluid flowcontrol system of claim 1, wherein the controller comprises a hardwarecontroller.
 13. The fluid flow control system of claim 1, wherein thecontroller comprises a field-programmable gate array.
 14. The fluid flowcontrol system of claim 1, wherein the first fluid comprises one or moreof oxygen, nitrous oxide, and air.
 15. The fluid flow control system ofclaim 1, further comprising a manual override selector configured tocause the fluid flow control system to enter the manual mode whenselected.
 16. A method for providing a backup manual control for theflow of fluid in a flow control system, comprising: detecting that aflow control system is in an electronic mode; receiving a selection of aflow rate of a fluid via an electronic flow control selector; encodingthe received selection of a flow rate as an electronic signal using anencoder; transmitting a control signal via a controller to an electronicflow control valve based on the encoded selection of a flow rate tocause the electronic flow control valve to allow the fluid to flow atthe selected flow rate; inhibiting the flow of the fluid through amechanical flow control valve; inhibiting the operation of a manual flowselector associated with the mechanical flow control valve; andreceiving an instruction to enter a manual mode, and then: inhibitingthe flow of the fluid through the electronic flow control valve;enabling the operation of the manual flow selector; and mechanicallyadjusting the flow rate of the fluid via the mechanical flow controlvalve in response to an adjustment of the manual flow selector.
 17. Themethod of claim 16, wherein inhibiting the operation of the manual flowselector comprises retracting the manual flow selector when the flowcontrol system is in the electronic mode, and wherein enabling theoperation of the manual flow selector comprises deploying the manualflow selector when the flow control system is in the manual mode. 18.The method of claim 16, wherein inhibiting the operation of the manualflow selector comprises locking the manual flow selector when the flowcontrol system is in the electronic mode to prevent adjustments, andwherein enabling the operation of the manual flow selector comprisesunlocking the manual flow selector when the flow control system is inthe manual mode to allow adjustments.
 19. The method of claim 16,wherein inhibiting the flow of the fluid through the electronic flowcontrol valve when the flow control system is in the manual mode andinhibiting the flow of the fluid through a mechanical flow control valveflow control system is in an electronic mode is performed using adiversion valve system comprising at least one of a three-way selectorvalve, a normally-open valve, and a normally-closed valve.
 20. Themethod of claim 16, wherein the fluid comprises a gas and furthercomprising vaporizing an anesthetic into the gas.
 21. The method ofclaim 16, wherein the electronic flow control valve comprises anelectronic proportional valve.
 22. The method of claim 16, wherein themechanical flow control valve comprises a needle valve.
 23. The methodof claim 16, wherein the mechanical flow control valve comprises aneedle valve and the electronic flow control valve comprises a steppermotor configured to electronically control the needle valve.
 24. Themethod of claim 16, wherein the manual flow selector comprises arotatable knob.
 25. The method of claim 16, wherein the fluid comprisesone or more of oxygen, nitrous oxide, and air.
 26. The method of claim16, wherein receiving an instruction to enter a manual mode comprisesreceiving an instruction from a manual override selector configured tocause the flow control system to enter the manual mode.
 27. The methodof claim 16, wherein receiving an instruction to enter a manual modecomprises detecting that the flow control system is in an unpoweredstate.
 28. The method of claim 16, wherein receiving an instruction toenter a manual mode comprises detecting an error in the electronic mode.